Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

Study information

Scientific title

Acronym

Study hypothesis

What is the effect of treatment with the antihypertensive agents lisinopril and labetalol on baroreflex sensitivity (BRS) in patients with previous stroke or transient ischaemic attack (TIA)?

Ethics approval

Not provided at time of registration

Study design

Randomised controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Not specified

Trial type

Not Specified

Patient information sheet

Condition

Cardiovascular: Stroke

Intervention

Our hypothesis is that treatment with the antihypertensive agents lisinopril and labetalol produces an improvement in baroreflex sensitivity in stroke patients.

All patients seen on the rapid access stroke clinic or discharged home from the acute stroke unit with a diagnosis of stroke in whom the physician responsible for their care considers antihypertensive agents are indicated will be considered for this study. If they fulfill the inclusion criteria, have none of the exclusion criteria and give consent then they are entered into the trial.

Participants will receive lisinopril and labetalol consecutively in a randomly allocated order with a 2 week washout period between each treatment. The dose of each drug will be carefully titrated up until the desired response in blood pressure is seen (a fall in systolic blood pressure of 10mmHg). Periods of monitoring will be conducted immediately prior to each treatment and after they have been on their target dose for 14 days.

A flow chart summarising what will happen to each participant is included at the end of the study protocol.

The period of monitoring will involve initially 2 periods of casual blood pressure (BP) monitoring (3 readings repeated 10 minutes apart). Participants will then undergo recording of beat-to-beat blood pressure monitoring, using the Portapres non-invasive BP recording device. This involves the application of an inflatable cuff to the finger, which can cause some tingling, but should not cause any discomfort. At the same time, an ECG monitor is attached, and respiratory frequency is measured by means of an abdominal wasteband. 3 sequential readings are taken using this equipment, and analysis of this data using spectral and sequence analysis methods provides an estimate of BRS. Participants will also have recordings of central arterial stiffness performed using applanation tonometry to obtain information on arterial waveforms and pulse wave velocity. This is a non-invasive technique which involves the application of a probe over the radial artery at the wrist, the carotid artery in the neck, and the femoral artery in the groin (although there will be no need to remove undergarments). This period of monitoring should take approximately one hour.

Each participant will also have the following data collected: The severity of their stroke (using the NIH stroke scale), stroke classification, side of the lesion, neuroimaging findings, presence of carotid artery disease, vascular risk factors and past vascular events.

Throughout the study, participants will be monitored for side effects related to their trial medication such as symptomatic bradycardia or hypotension. Blood tests will also be taken prior to commencing treatment and after 1 week to check for any deterioration in renal function. If any side effects occur, the treatment will be withdrawn.

In view of the scientific nature of the studies, their designs have been guided by perceived gaps in current medical literature, rather than direct user involvement. However, a detailed patient information leaflet, and an opportunity to ask questions, will be provided.

The methods used for obtaining BRS and arterial compliance information have been used extensively in other trials, in both stroke patients, and other clinical conditions.

Intervention type

Drug

Phase

Not Specified

Drug names

lisinopril, labetalol

Primary outcome measures

Change in BRS seen as a result of treatment with lisinopril and labetalol.

Secondary outcome measures

Not provided at time of registration

Overall trial start date

07/01/2005

Overall trial end date

31/08/2006

Reason abandoned

Eligibility

Participant inclusion criteria

Patients with previous stroke or transient ischaemic attack (TIA).1. Age > 18 years